Yes, Vishnu is mentioned in Jainism, but with a different context than in Hinduism. In Jainism, the term "Vasudeva" is used instead of "Vishnu," and it refers to a particular type of heroic personality, not to the supreme deity as in Hinduism.

According to Jain universal history, there are 63 illustrious beings known as the "Shalaka Purushas." Among these, there are 9 sets of "Triads" consisting of a Tirthankara, a Chakravarti (universal monarch), and a Vasudeva (a powerful hero), and each Vasudeva is sometimes identified with Vishnu in popular usage. The most well-known Vasudeva is Shri Krishna, who is considered the ninth Vasudeva in Jain tradition.

However, Jainism does not worship Vishnu (or Vasudeva) as a supreme god. Instead, these figures are respected as great souls (Mahapurushas) who play a significant role in the cosmic cycles but are still bound by karma and the cycle of birth and death, unlike the Tirthankaras who attain liberation (moksha).

So, Vishnu/Vasudeva is mentioned in Jain texts, but the concept and role are quite different from those in Hinduism. Worship in Jainism is primarily directed towards the Tirthankaras and not to Vasudevas like Vishnu or Krishna.